Bitcoin cannot crash nor go down against the dollar. You can print as much US dollars or fiat currency as you want. BUT YOU CANT CREATE MORE THAN 21 MILLION BITCOINS. If everyone just realize that fact, it would never stop going up. It seems like the idiot stupid fools that are selling since December don't know that. It is just as simple as that.
Those selling are just afraid that they are going to lose all the money that they spent investing into bitcoins, they have no foreknowledge about it's potential, they were just in to make some profits and that's all.
Yes it is important to have good knowledge and updates about the market and then should take the decision according to the news, but i think it is not so easy to predict about the bitcoin price that either it is going to crash to will make a new historical increase in its price, but with the increasing investors of bitcoin we can predict that bitcoin is becoming more stronger from time to time and therefore bitcoin position is now become more stronger and will not go to crash so easily.